diff -r e0d59f0c2b7d -r 22ee476cc664 src/hotspot/share/memory/archiveUtils.cpp --- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/src/hotspot/share/memory/archiveUtils.cpp Wed Nov 13 16:36:54 2019 -0800 @@ -0,0 +1,118 @@ +/* + * Copyright (c) 2019, Oracle and/or its affiliates. All rights reserved. + * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. + * + * This code is free software; you can redistribute it and/or modify it + * under the terms of the GNU General Public License version 2 only, as + * published by the Free Software Foundation. + * + * This code is distributed in the hope that it will be useful, but WITHOUT + * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or + * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License + * version 2 for more details (a copy is included in the LICENSE file that + * accompanied this code). + * + * You should have received a copy of the GNU General Public License version + * 2 along with this work; if not, write to the Free Software Foundation, + * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. + * + * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA + * or visit www.oracle.com if you need additional information or have any + * questions. + * + */ + +#include "precompiled.hpp" +#include "memory/archiveUtils.hpp" +#include "memory/metaspace.hpp" +#include "utilities/bitMap.inline.hpp" + +#if INCLUDE_CDS + +CHeapBitMap* ArchivePtrMarker::_ptrmap = NULL; +address* ArchivePtrMarker::_ptr_base; +address* ArchivePtrMarker::_ptr_end; +bool ArchivePtrMarker::_compacted; + +void ArchivePtrMarker::initialize(CHeapBitMap* ptrmap, address* ptr_base, address* ptr_end) { + assert(_ptrmap == NULL, "initialize only once"); + _ptr_base = ptr_base; + _ptr_end = ptr_end; + _compacted = false; + _ptrmap = ptrmap; + + // Use this as initial guesstimate. We should need less space in the + // archive, but if we're wrong the bitmap will be expanded automatically. + size_t estimated_archive_size = MetaspaceGC::capacity_until_GC(); + // But set it smaller in debug builds so we always test the expansion code. + // (Default archive is about 12MB). + DEBUG_ONLY(estimated_archive_size = 6 * M); + + // We need one bit per pointer in the archive. + _ptrmap->initialize(estimated_archive_size / sizeof(intptr_t)); +} + +void ArchivePtrMarker::mark_pointer(address* ptr_loc) { + assert(_ptrmap != NULL, "not initialized"); + assert(!_compacted, "cannot mark anymore"); + + if (_ptr_base <= ptr_loc && ptr_loc < _ptr_end) { + address value = *ptr_loc; + if (value != NULL) { + assert(uintx(ptr_loc) % sizeof(intptr_t) == 0, "pointers must be stored in aligned addresses"); + size_t idx = ptr_loc - _ptr_base; + if (_ptrmap->size() <= idx) { + _ptrmap->resize((idx + 1) * 2); + } + assert(idx < _ptrmap->size(), "must be"); + _ptrmap->set_bit(idx); + //tty->print_cr("Marking pointer [%p] -> %p @ " SIZE_FORMAT_W(9), ptr_loc, *ptr_loc, idx); + } + } +} + +class ArchivePtrBitmapCleaner: public BitMapClosure { + CHeapBitMap* _ptrmap; + address* _ptr_base; + address _relocatable_base; + address _relocatable_end; + size_t _max_non_null_offset; + +public: + ArchivePtrBitmapCleaner(CHeapBitMap* ptrmap, address* ptr_base, address relocatable_base, address relocatable_end) : + _ptrmap(ptrmap), _ptr_base(ptr_base), + _relocatable_base(relocatable_base), _relocatable_end(relocatable_end), _max_non_null_offset(0) {} + + bool do_bit(size_t offset) { + address* ptr_loc = _ptr_base + offset; + address ptr_value = *ptr_loc; + if (ptr_value != NULL) { + assert(_relocatable_base <= ptr_value && ptr_value < _relocatable_end, "do not point to arbitrary locations!"); + if (_max_non_null_offset < offset) { + _max_non_null_offset = offset; + } + } else { + _ptrmap->clear_bit(offset); + DEBUG_ONLY(log_trace(cds, reloc)("Clearing pointer [" PTR_FORMAT "] -> NULL @ " SIZE_FORMAT_W(9), p2i(ptr_loc), offset)); + } + + return true; + } + + size_t max_non_null_offset() const { return _max_non_null_offset; } +}; + +void ArchivePtrMarker::compact(address relocatable_base, address relocatable_end) { + assert(!_compacted, "cannot compact again"); + ArchivePtrBitmapCleaner cleaner(_ptrmap, _ptr_base, relocatable_base, relocatable_end); + _ptrmap->iterate(&cleaner); + compact(cleaner.max_non_null_offset()); +} + +void ArchivePtrMarker::compact(size_t max_non_null_offset) { + assert(!_compacted, "cannot compact again"); + _ptrmap->resize(max_non_null_offset + 1); + _compacted = true; +} + +#endif // INCLUDE_CDS